package com.stylefeng.guns.core.util;

import com.stylefeng.guns.core.exception.GunsException;
import com.stylefeng.guns.core.exception.GunsExceptionEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class FileUtil {

    private static Logger log = LoggerFactory.getLogger(FileUtil.class);

    /**
     * NIO way
     */
    public static byte[] toByteArray(String filename) {

        File f = new File(filename);
        if (!f.exists()) {
            log.error("文件未找到！" + filename);
            throw new GunsException(GunsExceptionEnum.FILE_NOT_FOUND);
        }
        FileChannel channel = null;
        FileInputStream fs = null;
        try {
            fs = new FileInputStream(f);
            channel = fs.getChannel();
            ByteBuffer byteBuffer = ByteBuffer.allocate((int) channel.size());
            while ((channel.read(byteBuffer)) > 0) {
                // do nothing
                // System.out.println("reading");
            }
            return byteBuffer.array();
        } catch (IOException e) {
            throw new GunsException(GunsExceptionEnum.FILE_READING_ERROR);
        } finally {
            try {
                channel.close();
            } catch (IOException e) {
                throw new GunsException(GunsExceptionEnum.FILE_READING_ERROR);
            }
            try {
                fs.close();
            } catch (IOException e) {
                throw new GunsException(GunsExceptionEnum.FILE_READING_ERROR);
            }
        }
    }

    /**
     * 删除目录
     *
     * @author fengshuonan
     * @Date 2017/10/30 下午4:15
     */
    public static boolean deleteDir(File dir) {
        if (dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
        }
        return dir.delete();
    }
    /**
     * 向文件中写入内容
     * @param filepath 文件路径与名称
     * @param newstr  写入的内容
     * @return
     * @throws IOException
     */
    public static boolean writeFileContent(String filepath,String newstr) throws IOException{
        Boolean bool = false;
        String filein = newstr+"\r\n";//新写入的行，换行
        String temp  = "";

        FileInputStream fis = null;
        InputStreamReader isr = null;
        BufferedReader br = null;
        FileOutputStream fos  = null;
        PrintWriter pw = null;
        try {
            File file = new File(filepath);//文件路径(包括文件名称)
            //将文件读入输入流
            fis = new FileInputStream(file);
            isr = new InputStreamReader(fis);
            br = new BufferedReader(isr);
            StringBuffer buffer = new StringBuffer();

            //文件原有内容
            for(int i=0;(temp =br.readLine())!=null;i++){
                buffer.append(temp);
                // 行与行之间的分隔符 相当于“\n”
                buffer = buffer.append(System.getProperty("line.separator"));
            }
            buffer.append(filein);

            fos = new FileOutputStream(file);
            pw = new PrintWriter(fos);
            pw.write(buffer.toString().toCharArray());
            pw.flush();
            bool = true;
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally {
            //不要忘记关闭
            if (pw != null) {
                pw.close();
            }
            if (fos != null) {
                fos.close();
            }
            if (br != null) {
                br.close();
            }
            if (isr != null) {
                isr.close();
            }
            if (fis != null) {
                fis.close();
            }
        }
        return bool;
    }
}